Improvement in chemical fire-engines



:jij

M4 PErERS. PH010-LTHOGRAPHER WASHINGTON o C NITED VSTATES PATENT FFICE.

ISAAC II. CLARK, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO PAUL I. TODD, OF SAME PLACE.

IMPROVEMENT IN CHEMICAL lFIRE-ENGINES.

Specification forining part of Letters Patent No. 90,637, dated June l, 1869.

To all to whom these presents shall come Be it knownv that I, ISAAC H. CLARK, of Boston, in the county of Suffolk and Commonwealth of Massachusetts, have made an invention of certain Improvements in Chemical Fire-Engines, so called; and do hereby declare the following to be a full, clear, and

exact description thereof', due reference being had to the accompanying drawings, making part of this specification, and in which- Figure 1 is a vertical central and longitudinal section, Fig. 2 a transverse section, and Fig. 3 a horizontal section, of an apparatusin which my invention is embodied. Fig. 4L is a representation of a modification of the invention, to be hereinafter referred to.

This invention relates to a class of fire-engines now coming into general use known as chemical fire-engines,77 or those vin which various chemical agents, which in themselves or in their gaseous products are destructible to combustion, are employed in combination with the water thrown by such engine to subdue flame either on land or on shipboard, the purpose of the invention being primarily to relieve the pumps of the engine from the corrosive action of the chemical ingredients, and, secondari1y,to preserve the ingredients in an inert condition until they come directly in contact with lthe fiames to be extinguished.

The invention consists in constructing the air-chamber of a fire-engine (otherwise of ordinary construction) in such manner that it shall serve the double purpose of an air-chamber and of holding in suspension within it the chemical ingredients to be conveyed therefrom by the water, and in combining with the pumps and the tub of the engine a pipe with two inlet-orifices, one conveying water from the exterior of the engine directly and the other from the interior of the tub, both inlets being regulated by one valve, and operating as hereinafter explained, the discharging-outlet of the air-chamber being combined therewith in any well-known manner.

In the drawings before mentioned as accompanying this specification, and which illustrate my invention, A denotes the body of a tub; B B, the pumps, C, the air-chamber, and C the discharging-pipe of the latter, such parts being arranged and provided with the ordinary working beam and brakes, and operating in manner similar to fire-engines now in use.

In carrying out my invention I dispose within the air-chamber C, and preferably at its upper part, a receptacle or means of holding in suspension therein the chemical ingredients or combination of ingredients, such means bein in the present instance, and as shown at D in the drawings, a foraminous or gauze basket fixed within the interior of the air-chamber, and, as before premised, at the upper part thereof', a filling-orifice, a, being formed in the upper part of such air-chamber, and communicating with the basket D, for the purpose of allowing the desired substances to be deposited within the latter, the orifice a being provided with a screw-plug, I), for securely closing it.

c inthe accompanying drawings represents the suction or feed pipe as extending from the exterior of the engine into and through its tub, and into the'base or valve-box of the airchamber in the usual manner. The pipe c has a branch inlet-pipe, d, applied to or making part of it, such pipe communicating with the interior of the tub of the engine. A cock or valve, e, is situated at the point of intersection, this valve being of such construction as to be capable of opening communication between either of the pipes c and d and the pumps of the engine, and to cut off communication of the other therewith, in order that the water maybe supplied to such pump, either from the exterior of the pipe c or from the interior of the tub, by means of the pipe d.

In practical use of the above-described engine, water supplied to the air-chamber C by means of the pumps B B in the ordinary manner, and through one of the pipes c or d, comes in contact with the chemical ingredient contained in such air-chamber, such ingredients or their gaseous products being gradually absorbed by and conveyed with the'water issuing from the engine.

I would remark that in place of one gauze or foraminous cylinder or cage for containing the chemical ingredients, as shown in the drawings, two or more may be adopted, in order to hold ingredients of' different characters.

The chemicals deposited within the airchamber may beof lsuch naturethat, though i' combined, they shall remain A-in a normal lor inert condition until they come in contact with the flames to be subdued, when they shall cre-v ate and exhale a powerful gas directly upon the names, by which means nearly the entire amount of combustion-destroying gas is'econ, omized which is now 10st in transit, the-stream of water being the vehicle for precipitating the chemical compound upon the fire.

As the chemical ingredients employed in the above-described engine at no time come in con. tact with the pumps thereof, the corrosive andr` destructive action of these chemicals upon the pumps is entirely avoided, which fact constitutes an important advantage in my invention, as it enables me t0 adapt an ordinary re-engine, with very little expense, to the purposes before explained.

Various means other thanthe` basket o before mentioned may be adopted for confining the chemical material or compound within the air-chamber c, without alfecting the characteristic feature of my invention, which, as'before` prefaced, consists in making the air-chamber of a fire engine the receptacle of chemical agents. For instance, a foraminous orgauze shelf may be placed acrossthe interior of the,

air-chamber, upon which the chemicals may be deposited; or such shelf' may be composed f .of solid metal, having an orifice made through it -forescapeof thechemicals, such orifice being .provided with a titillating-valve, as shown in Fig. 4 of the accompanying drawings, the ebullition of the inrushing water within the air-chamber. producing such vibrations of the stem of the valve as to cause intermittent partial-openings ofthe orice sufficient to aly 1owof1a-gradual escape of the chemical substances through such orifice.'

.Havingfthus describedthe nature and operation of what I consider to be my invention, I claim as such invention, and desire to secure by Letters Patent of the United States, as follows:

Claims. 

